Don't know if this will help you or not but figured I'd throw it out there.

When I set up an AC system I usually mock my rubber lines up with heater hose first. I go ahead and loosely install the fitting I’m going to be using where they need to go. Depending on the fitting, usually 1/2, 5/8, or 3/4 inch heater hose will slip into the fittings. As the heater hose has usually been stored in a coil it has a natural curve to it like the AC hose does and this can be an advantage as you can often make that curve work for you when laying out the hose (trying to bend the AC hose against the curve to make it lay the way you want can be a big PIA).

I usually start out with the heater hose a bit on the long side then trim it to the correct length when it’s fully seated in the AC fitting. Once I’m happy with the line layout I take a marker and draw a line on the fitting and hose so I know how the fitting are supposed to be oriented in case they get bumped when I take them into the parts store to have the actual line made. That’s especially critical if you have a hose with an angled fitting on both ends that HAVE to be properly indexed from each other to work.

When I take them into the parts store to have the lines made up I tell them to make the lines the same length as the heater hose. On the lines that have an angled fitting on them I tell them to make sure the curvature of the AC hose is oriented the same direction as the as the curve on the heater hose.

For me it works like a charm, once I get the hoses back they always end up fitting and are the correct length. Make sure you tell them you want the heater hoses back…….that way you can lay the piece of heater hose on top of the new AC line and verify they cut it to the right length and the fitting were oriented correctly before they were crimped. Depending on the length of the heater hose it can often be used to connect the heater core so it doesn’t go to waste.

All that being said, it’s been a long time since I bought heater hose so I don’t know how pricey it currently is. I do know it should be a lot cheaper than AC hose (besides being a lot easier to work with when mocking up the system). If you screw up on just one AC line and have to have it remade chances are that the replacement line and fittings would end up costing more than the cost of heater hose for mockup.